1. Technical Field of the Invention
The present invention relates to a technique for reading disk management information in a disk device.
2. Description of the Related Art
In read-only disks, such as CDs or ROMs, or recording medium, such as optical disks, mainly intended for recording audiovisual information, there is no area for, defect management made available in advance, and the processing method against any defect in the medium is determined on the system side as required. Unlike them, optical disks, such as DVD-RAMs, for which emphasis is placed on securing reliability at or above a certain level by standardizing the defect processing method, and erasable type disks, such as magnetic disks, are checked for defects sector by sector or on some other prescribed basis at the time of manufacture and supplied to the market in a state in which the addresses of sectors or other units containing the detected defects are recorded in a prescribed area. How to record management information on these defects is determined in a protocol governing the pertinent type of disk. An erasable disk conforming to the ISO/IEC 10089.13549 protocol, for instance, has defect management information consisting of defective sectors and substitute sectors therefor in two areas each at the inner and outer ends of the user area in the disk. Namely the disk holds altogether four sets of the same management information on the inner and outer circumferences. These areas are known as defect management areas (DMAs). In the following description, the defect management information mentioned above will be referred to as first management information. The aforementioned erasable disk conforming to the ISO/IEC 10089.13549 protocol also has two sets of file management information known as the universal disk format (UDF) at the inner and outer ends of the user area. In the following description, the aforementioned UDF will be referred to as second management information. In a conventional optical disk device for recording or reproducing information onto or out of this disk, when turning on power supply to the device and when inserting the disk, all the second management information recorded in the two areas at the inner and outer ends of the user area is read in after reading in all the first management information recorded in the two areas at the inner and outer ends. The reason why the same sets of information are recorded into a plurality of areas apart from each other is that in this way the reliability of the records themselves can be increased and the reproducibility of the management information can be enhanced against impediments (including fingerprints, dust and flaws) that may arise after the information is recorded.
When all the first management information and the second management information are read by the method described above into the erasable disk provided with medium management information areas on its inner and outer circumferences, the optical head should make at least one round trip between the inner and outer circumferences of the disk, resulting in a long time taken before the recording or reproduction of information can be started. This problem is especially conspicuous with optical disk devices in which the head travels more slowly than the magnetic head. Examples of related art are found in, for instance, in the Japanese Patent Applications Laid-open Nos. 11-25575 and 10-269709. The Japanese Patent Application Laid-open No. 11-25575 discloses a technique by which, when the device finds the medium to be erasable after power supply is turned on or the medium is inserted, it reads out DMA information on the inner circumference, then records and reproduces a pattern in a drive test zone on the inner circumference to adjust recording power, moves the pickup to another drive test zone on the outer circumference to adjust recording power similarly, and processes start-up by reading out DMA information on the outer circumference. The Japanese Patent Application Laid-open No. 10-269709 describes a technique by which, in a magnetic disk device using an inerasable magnetic disk, information on the assignment of substitutes for defective portions and information on associations between defective portions and substitutes are stored into an erasable non-volatile memory to reduce the time taken to access data and to eliminate the exhaustion of the backup battery. When an instruction is received from a superior device to read in or write in a range containing defective portions, the data and management information of the aforementioned sectors are read out of written into the non-volatile memory.
On the other hand a mobile video camera or the like, which is often required to record a contingent event in a hurry, keenly needs a reduction in the length of time taken to start up. This necessitates a further cutback on the processing time of management information and the like. To meet this requirement, a conventional disk device reads first management information (medium management information) on an optical disk when the optical disk is inserted, stores the information into a D-RAM or the like, and holds the first management information in the D-RAM or the like as long as the main power is on before the optical disk is ejected. In this manner, even if the disk revolution is stopped in the power saving mode when no demand for recording or reproduction comes for a long period of time, recording or reproduction, when it is resumed, can be done using the held first management information without having to read the first management information on the disk. However, once the main power is turned off, the management information stored in the D-RAM or the like is lost.
However, by the above-described technique of storing the first management information (medium management information) into a D-RAM or the like, the first management information can be held only while the main power is on, and once the main power is turned off, the previously held first management information is lost. Therefore, if the main power is once turned off and again turned onto perform recording or reproduction, even if the disk is neither inserted nor ejected, it is necessary to take time and read the prescribed management from the outset. On the other hand, the technique disclosed in the Japanese Patent Application Laid-open No. 10-269709 takes no account of disk insertion or ejection, and accordingly cannot be applied to a disk device for which the disk is replaced. Moreover, as the technique disclosed in this application performs erasion using a non-volatile memory which permits erasion only a relatively small number of times, the memory may become unusable soon.
Or if a battery-drivable CMOS memory or the like is used instead of a non-volatile memory to store information on the replacement of defect-containing sectors in a disk and data to be stored there, a capacity of about 10 MB is likely to be required, and this would necessitate a large-capacity battery for driving the memory, making it difficult to reduce the size and cost of the device. The technique described in the cited patent application also involves an unsolved problem that, when processing is to be resumed after the replacement of the disk or temporary suspension, the time take to acquire and process management information should be reduced to shorten the start-up time.
According to the prior art, for instance, if a disk is already in the device when the main power is turned on but there is not management information or the like regarding the disk, it will be necessary to take out of the management information necessary for recording or reproduction by reading the prescribed full course of reading management information. However, if there is already management information or the like regarding the disk already acquired by the disk device and the acquired information is reliable, that acquired information can be used. If the acquired information is unreliable, management information and the like on the disk should be read and confirmed at least one. In other words, the disk device should acquire device-related information which would serve as the basis of reliability. The required disk-related information includes: (1) is the inserted disk identified? (2) if identified, has the device acquired necessary management information regarding the identified disk? and (3) is the acquired management information reliable enough? Since the memories of the control system and others are operating in a state in which the main power is kept turned on, there will be no problem because information from (1) through (3) above is wholly held. However, if the main power is once cut off and again turned on, it will be necessary to check in a short period of time when the power is turned on again whether or not the disk that is currently in the device is the same as what was in when the main power was cut off, whether information regarding the disk that was in the device is held and, if it is, whether that information is reliable.
A problem to be solved by the present invention, in view of the status of the prior art described above, is to enable a disk device, even when processing is resumed after replacing the disk or cutting off the power supply, to reduce the start-up time by acquiring reliable information on the disk that is inserted in a short period of time, and thereby make it possible to start recording or reproduction quickly after the power supply is turned on.
An object of the invention is to provide a technique that can solve the problem noted above.
In order to solve the problem, according to the invention basically, in a disk device the effectiveness of management information recorded on a disk is judged; the finding of the judgment is stored into a memory means capable of keeping its content stored even when power supply is off; and when power supply is turned on, the management information is read out of some of a plurality of recording areas of the disk in advance of a recording or reproducing operation if the stored information on the finding of the judgment indicates effectiveness for the inserted disk. Also, in a disk device, disk insertion and ejection are detected or monitored; the finding of the detection of insertion or ejection is stored into a memory means capable of keeping its content stored even when power supply is off; and when power supply is turned on, effective management information is read out of some of a plurality of recording areas of the disk if disk insertion or ejection is detected from the stored information on the finding of the detection of insertion or ejection. Or in a disk device, the effectiveness of management information regarding disks is judged with respect to management information in some of the recording areas; the finding of the judgment is stored into a memory means capable of keeping its content stored even when power supply is off; and when power supply is turned on, the management information in that recording area judged to be effective is read if the stored information on the finding of the judgment indicates effectiveness for the inserted disk; and a recording or reproducing operation is started. More specifically, in a disk device, (1) the configuration is such that there are provided a judging means for judging the effectiveness of management information on a disk in recording or reproducing signals; a memory means capable of keeping its content stored even when power supply is off; and a control means for selecting the mode of reading the management information from the disk on the basis of information on the finding of the judgment, wherein the management information is read out of some of a plurality of recording areas of the disk in advance of a recording or reproducing operation if the stored information on the finding of the judgment indicates effectiveness for the inserted disk when power supply is turned on; (2) the configuration is such that there are provided a detecting means for detecting the presence or absence of a fitted disk; a judging means for judging the effectiveness of management information in recording or reproduction; a memory means capable of storing the finding of the judgment even when power supply is off; and a control means for selecting the mode of reading the management information from the disk on the basis of information on the finding of the judgment, wherein the management information is read out of some of a plurality of recording areas of the disk in advance of a recording or reproducing operation if the presence of a fitted disk is detected and the stored information on the stored finding of the judgment indicates effectiveness for the inserted disk when power supply is turned on; (3) the configuration is such that there are provided an insertion/ejection detecting means for detecting disk insertion and ejection; a memory means capable of storing the result of the detection of insertion or ejection even when power supply is off, and a control means for selecting the mode of reading the management information on the basis of the stored information on the result of the detection of insertion or ejection, wherein the management information is read out of some of the recording areas of the disk in advance of a recording or reproducing operation if neither insertion nor ejection of the disk is detected; (4) the configuration is such that there are provided a detecting means for detecting whether or not a disk is fitted, a judging means for judging the effectiveness of the management information for the disk in recording or reproduction, an insertion/ejection detecting means for detecting insertion or ejection of the disk, a memory means capable of storing the result of the detection of insertion or ejection and the finding of the judgment even when power supply is off, and a control means for selecting the mode of reading the management information on the basis of the stored information on the result of the detection of insertion or ejection and the finding of the judgment, wherein the management information is read out of some of the recording areas of the disk in advance of a recording or reproducing operation if the fitting of the disk is detected, the stored finding of the judgment indicates effectiveness for the inserted disk and neither insertion nor ejection of the disk is detected when power supply is turned on; (5) in the configuration of (4) above, the detecting means, the judging means and the control means operate on a first power source, the insertion/ejection detecting means and the memory means operate on a second power source and, when the first power source is turned on, selection regarding the mode of reading the management information is performed; (6) the configuration is such that there are provided a detecting means for detecting whether or not the disk is fitted, a judging means for judging the effectiveness of the management information in recording or reproduction with respect to management information recorded over a plurality of recording areas of the disk, a memory means capable of storing the finding of the judgment even when power supply is off, and a control means for selecting the mode of reading the management information from the disk on the basis of the stored information on the finding of the judgment, wherein, if the fitting of the disk is detected and the stored information on the finding of the judgment indicates effectiveness for the inserted disk when power supply is turned on, the management information is read out of that area indicated to be effective and a recording or reproducing operation is started; (7) the configuration is such that there are provided a detecting means, operating on a first power source, for detecting whether or not the disk is fitted; a judging means, operating on the first power source, for judging the effectiveness of the management information in the recording or reproduction; a memory means, operating on a second power source, for storing the finding of the judgment; and a control means, operating on the first power source, for selecting the mode of reading the management information on the basis of the stored information on the finding of the judgment, wherein, when the first power source is turned on, if the fitting of the disk is detected and the stored information on the finding of the judgment indicates effectiveness for the inserted disk, effective management information is read out of either a first area or a second area of the disk or, if it indicates ineffectiveness, the management information is read out of both the first area and the second area; (8) the configuration is such that there are provided a detecting means for detecting whether or not a disk is fitted, an insertion/ejection detecting means for detecting insertion or ejection of the disk, a memory means capable of storing the result of the detection of insertion or ejection even when power supply is off, and a control means for selecting the mode of reading the management information on the basis of the stored information on the result of the detection of insertion or ejection, wherein effective management information is read out of some of a plurality of recording areas of the disk if the fitting of the disk is detected and neither insertion nor ejection of the disk is detected when power supply is turned on; (9) in the configuration of any of (1) through (8) above, the plurality of areas in which management information is recorded are divided between the inner circumferential part and the outer circumferential part of the disk; (10) in the configuration of any of (1) through (8) above, the plurality of areas in which management information is recorded are four areas, and control is so effected that management information be read from one of these areas; (11) in the configuration of any of (1) through (8) above, the management information consists of a first set of management information for managing the state of the disk itself and a second set of management information for managing data information recorded on the disk for eventual reproduction, and the first and second sets of management information are recorded on a distributed basis in the inner circumferential area and the outer circumferential area of the disk, and control is so effected that the first and second sets of management information be read out of either of these areas; (12) the configuration is such that there are provided a recording means for recording the management information in first and second areas of the disk; a judging means for judging the effectiveness of the management information, a memory means capable of storing the finding of the judgment even when power supply is off, and a control means for selecting the mode of reading the management information from the disk on the basis of the stored information on the finding of the judgment, wherein the management information is read out of either of the first and second areas in advance of recording or reproducing the signals if the stored information on the finding of the judgment indicates effectiveness for the inserted disk or, if it indicates ineffectiveness of the management information, the management information is read out of both the first and the second areas; and (13) in the configuration of any of (1) through (8) above, the recorded or reproduced signals are information signals from a camera image pickup device. Further as an information processing terminal device, (14) the configuration is such that there are provided an interface for information transmission, an information processing means for processing information, a disk device for recording and/or reproducing the processed information onto or out of a disk on which management information of the same contents is multiply recorded over a plurality of areas, and a display means, wherein the disk device comprises a judging means for judging the effectiveness of the management information in recording or reproducing the signals, a memory means capable of storing the result of the judgment even when power supply is off, and a control means for reading management information out of some of the recording areas of the disk in advance of the recording or reproducing operation if the stored information on the finding of the judgment indicates effectiveness for the inserted disk. (15) The configuration may as well be such that there are provided an interface for information transmission, an information processing means for processing information, a disk device for recording and/or reproducing the processed information onto or out of a disk on which management information of the same contents is multiply recorded over a plurality of areas, and a display means, wherein the disk device comprises an insertion/ejection detecting means for detecting insertion or ejection of the disk, a memory means capable of storing the result of the detection of insertion or ejection of the disk even when power supply is off, and a control means for reading effective management information out of some of the recording areas of the disk if neither insertion nor ejection of the disk is detected. Further as a method of controlling the reading of management information in a disk device, (16) the reading of the management information is controlled through a step of reading the management information in advance of recording or reproducing the signals, a step of judging the effectiveness of the read management information, a step of storing the finding of the judgment into a memory means capable of storing even when power supply is off, a step of determining whether or not the stored information of the finding of the judgment indicates effectiveness for the inserted disk, and a step of reading management information out of some of the recording areas of the disk if the stored information on the result of the determination indicates effectiveness for the inserted disk. (17) The reading of the management information is controlled through a step of detecting insertion or ejection of a disk, a step of storing the result of detection into a memory means capable of storing even when power supply is off, and a step of reading effective management information out of some of the recording areas of the disk if the stored information on the result of the detection of insertion or ejection indicates neither insertion nor ejection of the disk.
The control means, when the main power is turned on, selects a short-time for the reading of management information on the basis of the result of detection of disk insertion or ejection or the result of the determination of the effectiveness of the management information for the disk, and thereby reduces the length of time required for start-up.